This paper aims at demonstrating that “Parkinson’s disease” (PD) is an umbrella designation for a number of heterogeneous disorders sharing an important number of clinical features, but separated by significant differences.
In fact, PD should probably be regarded as a “Parkinson’s disease cluster”, and the core clinical features termed Parkinson Syndrome. Disease manifestations, genetic underpinnings, and pathological findings argue against a unique disease process and, hence, a unique management approach, especially one that aims solely at the improvement of later (i.e. motor) disease manifestations.
We propose that true therapeutic innovation in PD calls for a leap in concepts and shift in research efforts. Disease-specific neuroprotective agents targeting early molecular and pathological events should ideally be developed.

Similarly to Alzheimer’s disease (AlzD), the prevalence of PD is growing in the aging population. The lack of available neuroprotective interventions contributes to the general apprehension regarding the rising prevalence of age-related brain disease. Nonetheless, unlike the research carried out in AlzD, where novel drugs have been designed to target specific molecular disease mechanisms (without clinical success so far), no similar effort has been seen for PD yet. The lack of reproducible biomarkers used to detect disease early in its course, and to monitor its progression, is a major obstacle. A-synuclein in the cerebrospinal fluid is promising, but there are still some aspects to address before it can be reliably used. Other diagnostic
strategies may be used to further improve early diagnosis of PD.

http://ijcnmh.arc-publishing.org/upl...h.2014.1.7.pdf